The present invention relates to the field of mobile communications and, more particularly, to client data delivery using session initiation protocol (SIP) messages addressed with the static unique identifier of a mobile device.
The rise in popularity of mobile devices (e.g., smart phones, tablets, laptops, etc.) has correspondingly increased the quantity of available client/server software applications (e.g., email, instant messaging, games, etc.) or services for these platforms. Many of these mobile devices 105 receive their data 135 from a provider 130 over an Internet protocol (IP) based mobile communications network 115, as shown in FIG. 1. Every mobile device 105 has one or more hardware components that house one or more static, unique identifiers 110 like its mobile directory number (MDN).
For example, the subscriber identification module or SIM card of a mobile phone 105 contains within its memory an internationally-unique identifier (IMSI) for the subscriber. An electronic serial number of the mobile device 105 may be stored in its permanent memory.
The IP-based mobile communications network 115 uses the static, unique identifier 110 to communicate and track the mobile device 105 as it moves throughout the network 115. In order to interface with IP-based components, the IP-based mobile communications network 115 dynamically assigns the mobile device 105 an IP address 140 from an IP address pool 125 and records the assignment in an IP correlation table 120. The assigned IP address 140 is then used to identify data messages 135 for the mobile device 105 like those from the provider 130 as shown in FIG. 1.
The IP-based mobile communications networks 115 must then correlate the IP address 140 of a data message 135 from provider 130 to the appropriate static, unique identifier 110 to route the data message 135 to the mobile device 105. The primary issue faced by provider 130 using a conventional IP-based mobile communications network 115 is the dynamic nature of the IP address 140 with respect to the mobile device 105.
That is, the IP address 140 of the mobile device 105 is prone to change as the mobile device 105 changes its physical location and/or connection to the IP-based mobile communications network 115. In order for provider 130 to be capable of providing data to the mobile device 105 as it becomes available, the provider 130 must keep track of the IP address 140 of the mobile device 105. This incurs additional overhead on the part of the provider 130 and may result in delivery problems.
Most IP-based mobile communications network 115 use a predefined time period that a data channel is allowed to be inactive before the channel is terminated. Since it is unknown when the provider 130 will be sending data messages 135 to the mobile device 105, the provider 130 must force the IP-based mobile communications network 115 to keep the data channel active (i.e., sending a “filler” message to the mobile device 105 at regular intervals). Unfortunately, this approach increases resource consumption by the mobile device 105, greatly reducing battery life.